A data storage device, in particular a data storage device using a non-volatile storage medium, includes a plurality of data blocks. Each data block includes a plurality of data pages, each data page is for storing data with at least one storage unit, and the storage unit may be 512 B (byte) or preferably 4 KB. Data blocks are also divided into empty data blocks (or spare data blocks) and non-empty data blocks (or in-use data blocks) depending on whether data is stored therein or not. For data management and access, the data storage device needs to establish and store a host-to-flash physical address (H2F) mapping table, which is simply referred to as a mapping table in the present invention. When the data storage device is in operation, the mapping table is copied to a dynamic random access memory (DRAM) to increase the efficiency of data management and access. In addition, depending on the size of recorded content, in general the size of the mapping table is 1/1000 of the data storage capacity of the data storage device. For example, if the size of a data storage device is 256 GB, the size of the corresponding mapping table is 256 MB. Therefore, to store an entire mapping table, the size of the DRAM is preferably greater than or equal to 256 MB.
For a data storage device that is not provided with a DRAM or only provided with a small-sized DRAM (i.e., the DRAM is not large enough to store an entire mapping table), there is a technical need for providing a solution as to how to use static random access memory (SRAM) or small-sized DRAM for data management and access.